Method and apparatus for manufacturing semi-insulation GaAs monocrystal

DETAILED DESCRIPTION Accordingly, it is the object of the present invention to provide a method of manufacturing a semi-insulation GaAs monocrystal by controlling carbon concentration during crystal growth by a simple method, in order to manufacture a low-carbon concentration GaAs wafer required for devices such as Hall Sensors, FETs, HEMTs etc.
at a high production yield without deteriorating the semi-insulation characteristics thereof.
To achieve the above-mentioned object, the present invention provides a method of manufacturing a semi-insulation GaAs monocrystal in accordance with liquid encapsulated Czochralski method, which comprises the steps of: preparing a crucible formed with a crucible body and a small chamber communicating with a lower part of the crucible body, and a carbon heater processed to reduce surface blow holes thereof; putting a melted GaAs liquid and a sealing compound B.
sub.
2 O.
sub.
3 in the crucible housed in an airtight vessel in such a way that the sealing compound B.
sub.
2 O.
sub.
3 is on the melted GaAs liquid, the melted GaAs liquid put in the small chamber containing carbon to be supplied to the melted GaAs liquid put in the crucible body; heating the crucible by the heater housed in the airtight vessel; and pulling up the melted GaAs liquid from the crucible body by keeping the airtight vessel at a high pressure.
Further, the present invention provides a method of manufacturing a semi-insulation GaAs monocrystal in accordance with liquid encapsulated Czochralski method, which comprises the steps of: preparing a crucible formed with a crucible body and a small chamber communicating with a lower part of the crucible body, and a carbon heater processed to reduce surface blow holes thereof; putting a melted GaAs liquid and a sealing compound B.
sub.
2 O.
sub.
3 in the crucible housed in an airtight vessel in such a way that the sealing compound B.
sub.
2 O.
sub.
3 is on the melted GaAs liquid, moisture concentration of the sealing compound B.
sub.
2 O.
sub.
3 put in the small chamber being determined lower than that of the sealing compound B